In recent years, in reflection of the need for higher-speed communication and more compact communication devices, there has been an increasing demand for a lens array in which a plurality of lenses are arranged in parallel, as a compactly structured optical component effective for actualizing multichannel optical communication.
This type of lens array is conventionally configured such that a photovoltaic device including a plurality of light-emitting elements (such as a vertical cavity surface emitting laser [VCSEL]) can be attached thereto and a plurality of optical fibers can be attached thereto.
In a state in which the lens array is disposed between the photovoltaic device and plurality of the optical fibers in this way, the lens array optically couples light emitted from each light-emitting element of the photovoltaic device to an end face of each optical fiber. As a result, multichannel optical communication can be performed.
In addition, since the past, the photovoltaic device attached to this type of lens array has been problematic in that, as a result of changes in the output characteristics of the light from the light-emitting elements caused by the effects of temperature and the like, there is risk of disruption in appropriate transmission of communication information.
As a lens array intended to counter such problems, for example, a lens array such as that described in Patent Literature 1 has been proposed. In other words, in Patent Literature 1, some of the light emitted from the light-emitting elements and entering the lens array is reflected as monitor light by a reflection surface disposed on the optical path of the lens array. The reflected monitor light is converged by the lens faces and emitted towards light-receiving elements provided outside of the lens array. On the photovoltaic device side, output control of the light-emitting elements is performed based on the intensity and the amount of light of the monitor light received by the light-receiving elements, thereby stabilizing the output of the light-emitting elements.    Patent Literature 1: Japanese Patent Laid-open Publication No. 2006-344915